UNN Chemistry 2007/2008 Past Questions

Practice each question, then open it to see the full details.

Question 1

Two immiscible liquids with different boiling points can be separated by

A.the use of separating funnel
B.evaporation
C.distillation
D.decantation

Objective

Question 2

A mixture of CaCl₂ and CaCO₃ in water can be separated by

A.evaporation
B.sublimation
C.distillation
D.decantation

Objective

Question 3

Consider the reaction represented by
xPb(NO₃)₂ ---> 2PbO + yNO₂ + zO₂
What are the values of x, y and z respectively?

A.2, 6, 3
B.1, 4, 2
C.2, 4, 1
D.2, 4, 2

Objective

Question 4

20cm³ of H₂ mixed and separated with 100cm³ of air containing 21% O_{2A.31cm³
B.11cm³
C.90cm³
D.110cm³
Objective}

Question 5

What is responsible for metallic bonding?

A.Sharing of electrons between the metal atoms
B.Attraction between the atomic nuclei and the cloud of electrons
C.Transfer of electrons from one point to another
D.Attraction between positive and negative ions

Objective

Question 6

25cm³ of 1.5M solution of NaCl are added to 50cm³ of 3M NaCl. The molar concentration of the resulting solution is

A.2.5M
B.3M
C.2.25M
D.4.5M

Objective

Question 7

A solution of salt formed from HCl and NH₃ solutions is

A.acidic
B.basic
C.complex
D.neutral

Objective

Question 8

Which of the following elements will burn in excess oxygen to form a product that is neutral to litmus?

A.Carbon
B.Hydrogen
C.Sulphur
D.Sodium

Objective

Question 9

A current was passed for 10 mins and 0.2 mole of Cu was deposited. How many grammes of Ag will it deposit? [Cu = 64, Ag = 108]

A.43.2g
B.21.6g
C.10.8g
D.5.4g

Objective

Question 10

Pollution of underground water by metal ions is very likely in a soil that has high

A.acidity
B.alkalinity
C.chloride movement
D.nitrate content

Objective

Question 11

Producer gas is a gas with low calorific value because it contains more

A.CO₂ than O₂
B.N₂ than CO
C.CO₂ than N₂
D.N₂ than CO₂

Objective

Question 12

For most reversible reactions,

A.the reaction rate increases with time
B.the reaction rate decreases with time
C.the rate stabilizes with time
D.the rate produces a curve with time

Objective

Question 13

Which of the following compounds will leave a metal residue when heated?

A.Cu(NO₃)₂
B.AgNO₃
C.K₂CO₃
D.Na₂CO₃

Objective

Question 14

Which of the polymers contains nitrogen?

A.Nylon
B.PVC
C.Polyethene
D.Cellulose

Objective

Question 15

A red precipitate of copper(I)dicarbide is formed when ammonium solution of copper(I)chloride is introduced into

A.CH₂=CH-CH₂-CH₃
B.CH₃-CH₂-C-=CH
C.CH₃-CH₂-CH₂-CH₃
D.CH₃-C-=C-CH₃

Objective